Multilevel Modeling and Reasoning with FOML

Multilevel system modeling deals with the representation and implementation of relationships among types and among types and instances in software systems. It raises questions of interpretation and organization of types and instances in strict or interleaved layers. Reasoning over multilevel models requires a logic language that provides a uniform, extensible and flexible account for intra-type relationships, and type-instance relationships. FOML is a logic programming language that provides an expressive, executable formal basis for software models. It supports a wide variety of model-level activities, including reasoning about models, meta-modeling, and more. It is built as a semantic layer on top of PathLP, a compact logic programming language of guarded path expressions. In this paper we advocate the use of FOML as an underlying framework for the development and analysis of multilevel software modeling. We argue that FOML is suitable for multilevel modeling and for reasoning about such models. We show that FOML possesses major features needed for such tasks, including type-instance mixing in various organizational architectures, and demonstrate a sizable example using several approaches.